1. Field of the Invention
The present invention generally relates to dental handpieces having root canal apex-finding electrodes. More particularly, the present invention relates to such handpieces that feature movable and removable apex-finding electrodes.
2. Description of the Related Art
For treatment of a root canal during dental operations, a cutting tool, such as a reamer or file can be used to enlarge the root canal. In some configurations, the cutting tool also is used as a signal conductor in a circuit that measures the root canal length. In such configurations, a main control unit is electrically connected to the cutting tool with an electrode such that an electrical signal can be transmitted between the cutting tool and the control unit. The electrode physically contacts the cutting tool.
In some configurations, a circuit or wire is connected to the electrode and the circuit or wire extends outside of the handpiece to a connection to the control unit. Thus, the circuit or wire is external to the handpiece. In such a configuration, the circuit or wire requires manual manipulation to control its location and can get in the way when procedures are performed with the handpiece.
In other configurations, the circuit or wire extends through an internal portion of the handpiece and is removably connected to the electrode such that the electrode can be disconnected from the wire or circuit. In such a configuration, the manner in which the electrode is secured to the wire or circuit provides a limited contact region between the cutting tool and the circuit or wire. The limited contact region can result in inconsistent contact, which can impair performance of the handpiece.
In both configurations described above, sterilization of the dental equipment by autoclaving can be difficult, if not impossible, without removal of the electrode and any external wires or circuits.